Big3 Join 구분 Nested Loop Join Hash Join Sort Merge Join Optimizer Hint USE_NL(Table | Alias) USE_HASH(Table | Alias) USE_MERGE(Table | Alias) 조인조건 Any Join Equal Join 만 가능 Any Join(주로 Equal Join) init.ora Parameter .DB_BLOCK_BUFFERS .INDEX_COST_ADJUST .OPTIMIZER_INDEX_CACHING .HASH_JOIN_ENABLED .HASH_AREA_SIZE .HASH_MULTIBLOCK_IO_COUNT .SORT_AREA_SIZE .DB_..